Israel’s Prime Minister Benjamin Netanyahu unsuccessfully tried to block a Mossad briefing for US senators, which was aimed at warning the lawmakers that the new Iran sanctions bill could cause a collapse of nuclear talks, Time magazine revealed.

The briefing, which took place on January 19, included six US
officials traveling to Jerusalem for a meeting with Israeli
intelligence agency Mossad on the new Iran sanctions bill. Mossad
was to warn US lawmakers, among them Republican Senator John
McCain, that new sanctions could falter nuclear talks with
Tehran.

However, Netanyahu scrapped the meeting from his itinerary, Time
magazine reported on Saturday, citing unnamed sources close to
the events. In protest, the head of the Senate Foreign Relations
Committee, Tennessee Republican Bob Corker – who doesn’t favor
the introduction of additional sanctions on Iran – threatened to
cut short the US delegation’s trip to Jerusalem.

Corker addressed Israel's ambassador to the US, Ron Dermer,
asking him to intervene. Consequently, Netanyahu conceded and
allowed the briefing to take place, according to the report.

The Israeli PM's spokesman declined to comment on Time's inquiry
about the reason for Netanyahu's cancellation. The prime minister
is a strong supporter of a much tougher stance on Iran and its
nuclear program.

Bloomberg View reported on January 22 that Mossad indeed warned
Washington that the new sanctions bill, if approved by Congress,
could lead to a deadlock in talks with Iran.

Earlier in January, reports said that Mossad Chief Tamir Pardo
compared the effect of the new sanctions on the peace talks to
“throwing a grenade into the process.” Following the
report, Pardo's office issued a statement saying that he
"used this expression as a metaphor to describe the
possibility of creating a temporary crisis in the negotiations at
the end of which talks would resume under improved
conditions.”

Pardo “emphasized in the meeting [with US lawmakers in
January] that the exceptional effectiveness of the sanctions
imposed on Iran in recent years are what brought Iran to the
negotiating table," the statement read.

The bill, introduced on December 19 by Republican Mark Kirk and
Democrat Robert Menendez, calls for the enactment of new
sanctions if Iran cannot reach a consensus with the P5+1
countries in Geneva on curbing Tehran's nuclear program before
the June 30 deadline.

Though some US senators have been pushing to pass the
Kirk-Menendez bill, there are also those who oppose it –
particularly Corker, who is pushing forward his own legislation
which would require a Senate vote on any deal struck between the
P5+1 countries in Geneva.

A softer line was voiced by US Secretary of State John Kerry, who
told CBS News on Saturday that he hopes it is possible to reach
an interim political deal with Iran “in the next days,”
if Tehran can show that its nuclear program is intended for
peaceful purposes. The deal includes Iran curbing it’s most
sensitive nuclear activities for at least 10 years, in exchange
for the easing of some US sanctions.

"We believe very much that there's not anything that's going
to change in April or May or June that suggests that at that time
a decision you can't make now will be made then," Kerry
said.
"If it's peaceful, let's get it done. And my hope is that in the
next days that will be possible," he added.

Kerry and his Iranian counterpart, Mohammad Javad Zarif, are to
meet in Switzerland on Sunday to discuss Iran’s nuclear program.

The US secretary of state also slammed the letter written by 47
Republican senators to Iran last week as a "direct
interference.” The letter, written by Arkansas Senator Tom
Cotton, threatened to pull any nuclear deal reached with Iran,
once Obama leaves office.

Talks on Iran's nuclear program are scheduled to continue in
Switzerland next week, but little is known about the nuclear deal
being negotiated. According to reports, the agreement would allow
Iran to develop a civilian atomic program under strict
supervision, which would make it very difficult to build a
nuclear weapon.